tamer: ir::xir::reader: Parsing of child nodes

This is quick-and-dirty; refactoring can be done later on.  This is also
intended to demonstrate the ease with which additional events can be
added---the hard work is done.

tamer/src/ir/xir/reader.rs

@@ -111,6 +111,27 @@ impl<B: BufRead> XmlXirReader<B> {
                     ))
                 }
 
+                QuickXmlEvent::Start(ele) => {
+                    Some(ele.name().try_into().map_err(Error::from).and_then(
+                        |qname| {
+                            Self::parse_attrs(
+                                &mut self.tokbuf,
+                                ele.attributes(),
+                            )?;
+
+                            // The first token will be immediately returned
+                            //   via the Iterator.
+                            Ok(Token::Open(qname, DUMMY_SPAN))
+                        },
+                    ))
+                }
+
+                QuickXmlEvent::End(ele) => {
+                    Some(ele.name().try_into().map_err(Error::from).and_then(
+                        |qname| Ok(Token::Close(Some(qname), DUMMY_SPAN)),
+                    ))
+                }
+
                 // quick_xml emits a useless text event if the first byte is
                 //   a '<'.
                 QuickXmlEvent::Text(bytes) if bytes.escaped().is_empty() => {

tamer/src/ir/xir/reader/test.rs

@@ -172,6 +172,61 @@ fn permits_duplicate_attrs() {
     );
 }
 
+#[test]
+fn child_node_self_closing() {
+    let sut = Sut::new(r#"<root><child /></root>"#.as_bytes());
+
+    let result = sut.collect::<Result<Vec<_>>>();
+
+    assert_eq!(
+        result.expect("parsing failed"),
+        vec![
+            Token::Open("root".unwrap_into(), DUMMY_SPAN),
+            Token::Open("child".unwrap_into(), DUMMY_SPAN),
+            Token::Close(None, DUMMY_SPAN),
+            Token::Close(Some("root".unwrap_into()), DUMMY_SPAN),
+        ],
+    );
+}
+
+#[test]
+fn sibling_nodes() {
+    let sut = Sut::new(r#"<root><child /><child /></root>"#.as_bytes());
+
+    let result = sut.collect::<Result<Vec<_>>>();
+
+    assert_eq!(
+        result.expect("parsing failed"),
+        vec![
+            Token::Open("root".unwrap_into(), DUMMY_SPAN),
+            Token::Open("child".unwrap_into(), DUMMY_SPAN),
+            Token::Close(None, DUMMY_SPAN),
+            Token::Open("child".unwrap_into(), DUMMY_SPAN),
+            Token::Close(None, DUMMY_SPAN),
+            Token::Close(Some("root".unwrap_into()), DUMMY_SPAN),
+        ],
+    );
+}
+
+#[test]
+fn child_node_with_attrs() {
+    let sut = Sut::new(r#"<root><child foo="bar" /></root>"#.as_bytes());
+
+    let result = sut.collect::<Result<Vec<_>>>();
+
+    assert_eq!(
+        result.expect("parsing failed"),
+        vec![
+            Token::Open("root".unwrap_into(), DUMMY_SPAN),
+            Token::Open("child".unwrap_into(), DUMMY_SPAN),
+            Token::AttrName("foo".unwrap_into(), DUMMY_SPAN),
+            Token::AttrValue(AttrValue::Escaped("bar".into()), DUMMY_SPAN),
+            Token::Close(None, DUMMY_SPAN),
+            Token::Close(Some("root".unwrap_into()), DUMMY_SPAN),
+        ],
+    );
+}
+
 // TODO: Enough information for error recovery and reporting.
 #[test]
 fn node_name_invalid_utf8() {